He puts himself very visibly in every event, more than other promoters do. He puts out interviews on IFL way too regularly and has a personality of an Essex boy (which he is) and it's flash and off putting. He's also turning boxing into nights like darts events, lots of crowd atmosphere where possible (which works) and it can annoy people. He was pretty obnoxious in the Bellew Haye fight and it showed so there's always an angle people think he's playing (and he likely is). Essentially everyone is seeing through his act now and it's time to get serious with fight cards instead of selling utter tosh like he puts on a lot of undercards.
The fight alone would of got hearns money. It was a gamble, but he knew that time was on Joshua's side and that Joshua could come back from a loss to Wladimir.
Because Joshua can sell out stadiums fighting lesser opposition. Because Joshua is green, and before a fight with Wlad there was a real possibility he would get exposed. To a promoter, if that were to occur, they would be throwing many millions down the drain. A lot of promoters would not of taken that risk.
Wlad was still 41 years old and nothing like the Wlad of the past where if he had you hurt he finished you. Wlad was dangerous and experienced but he was still 41.